drf-spectacular: Add OpenApiResponse to a serializer-less function-based view

So, I'm documenting the following piece of code using drf-spectacular:

from rest_framework import response
from rest_framework.decorators import api_view, permission_classes
from rest_framework.response import Response
from rest_framework.permissions import AllowAny
from rest_framework import status

from drf_spectacular.utils import extend_schema, OpenApiParameter

def passcode_generator:
    return 0 # placeholder


@extend_schema(
    parameters=[
        OpenApiParameter(name="callsign", required=True, type=str),
    ],
    description="Get an APRS-IS passcode for a given callsign",
)
@api_view(["POST"])
@permission_classes([AllowAny])
def get_passcode(request):
    callsign = request.data.get("callsign", None)
    if callsign is None:
        raise Response(
            {"error": "Missing callsign"}, status=status.HTTP_400_BAD_REQUEST
        )
    return Response({"passcode": passcode_generator(callsign)})

What I can't understand how to do is how to document the responses. Namely, there is OpenApiResponse in drf_spectacular.utils but the documentation is very slim. How can I document the responses of my API with this system?

In the meanwhile, I found out a satisfying answer that also keeps automatic documentation generators happy:

I created a couple serializers:

from rest_framework import serializers


class CallsignSerializer(serializers.Serializer):
    callsign = serializers.CharField(max_length=200)


class PasscodeSerializer(serializers.Serializer):
    passcode = serializers.CharField(max_length=200)

And in the views (notice the comment before the last line):

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.permissions import AllowAny

from drf_spectacular.utils import extend_schema

from aprs.api.serializers import CallsignSerializer, PasscodeSerializer
from aprs.vendor.passcode import passcode_generator


class PasscodeView(APIView):
    """
    View to get the APRS passcode from a callsign
    """

    permission_classes = [
        AllowAny,
    ]

    serializer_class = CallsignSerializer

    @extend_schema(responses=PasscodeSerializer)
    def post(self, request):
        """
        Get the APRS passcode from a callsign
        """
        serializer = CallsignSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)

        callsign = serializer.validated_data["callsign"]
        passcode = passcode_generator(callsign)

        passcode_serializer = PasscodeSerializer(data={"passcode": passcode})
        passcode_serializer.is_valid(raise_exception=True)

        # The serializer isn't passed here directly because otherwise DRF's browsable API
        # will create a POST form for the PasscodeSerializer, instead of the
        # CallsignSerializer. It is used in the lines above, instead of passing a
        # dictionary here directly as a form of validation.
        return Response(passcode_serializer.validated_data)